Continuous-casting mold



Jan. 11, 1966 R. A. SCHULTZ CONTINUOUS-CASTING MOLD 2 Sheets-Sheet 1Filed April 12, 1963 INVENTOR.

Q Q 6 .2 O O O O H. o o 1 o o m n 9 d L| Attorney United States Patent3,223,071 CGNTINUQUS-CASHNG MUM Robert A. Schultz, Penn Hills Township,Allegheny County, Pa., assignor to United States Steel Corporation, acorporation of New Jersey Filed Apr. 12, 1963, Ser. No. 272,594 Claims.(ill. 22-512) This invention relates to a water-cooled mold suitable forthe continuous casting of slabs and, in particular, to a prismatic moldhaving end walls adapted to come and go with the side walls thereof onthermal expansion and contraction.

The problems associated with molds for the continuous casting of steelslabs are well set forth in Goss Patent No. 2,893,080. A further sourceof difficulty is the possible opening of the joints between side and endwalls of a mold made up of separate wall members, with the result thatmolten metal enters the opening and freezes therein.

I have invented an improved mold for the continuous casting of slabswhich overcomes the aforementioned difficulties and has furtheradvantages over molds previously known. In a preferred embodiment, Iprovide a mold having a pair or" base plates with supporting feetthereon and composed of side and end walls each of which includes aninner plate and an outer backing structure with a water-cooling passagetherebetween. The inner plates are secured to the backing structures byattachments similar to flexible staybolts distributed over their area.The end walls are slidably mounted on the backing structures of the sidewalls and move with the inner plates thereof on expansion orcontraction. I provide means for adjusting the end walls to a slightangle relative to the vertical, to provide a downward taper to the endsof the mold cavity.

A complete understanding of the invention may be obtained from thefollowing detailed description and explanation which refer to theaccompanying drawings illustrating the present preferred embodiment. Inthe drawmgs:

FIGURE 1 is a side elevation partly in section;

FIGURE 2 is an end elevation partly in section;

FIGURE 3 is a horizontal section taken along the plane of line IIIIII ofFIGURE 1; line 1-1 of FIGURE 3 indicates the plane on which the sectionof FIGURE 1 is taken;

FIGURE 4 is an enlarged portion of FIGURE 3;

FIGURE 5 is an enlarged portion through one of the attachments takenalong the line V-V of FIGURE 3; and

FIGURE 6 is a fragmentary isometric view of one of the supporting feet.

Referring now in detail to the drawings, my improved mold, indicatedgenerally at 18 is mounted on a pair of spaced supporting beams 11. Themold has spaced base plates 12 one resting on each beam 11. The spacingbetween the plates is governed by the width of the horizontal sectionthrough the mold cavity C. Feet 12a extend outwardly from plates 12. Thefeet of one of the plates 12 rest on blocks 12b bolted to one beam 11.Links 120 are pivoted to hearings on the bottom of the feet on the otherplate 12 and to bearings mounted on the other beam 11.

Spaced opposed side-wall backing structures 13 are upstanding on plates12. These structures are fabricated from steel plate and each comprisesan outer plate 14 with vertical side flanges 15 and intermediate flanges15a on the upper ends of which top plates 16 rest. Spaced horizontalwebs 16a intersect flanges 15a and abut flanges 15. Gusset plates 17(see FIGURE 6) extend outwardly from the lower ends of flanges 15 andthe adjacent flange a to plates 12. The inner edges of plates 12,flanges 15 and plates 16 extend beyond outer plate 14 toward the moldcavity and a mold side-wall plate 18 of copper or the like is therebyspaced inwardly away from plate 14, leaving a cooling-water passage Ptherebetween. The edges of flanges 15 and top and bottom plates 16 and12 engaged by plate 18 have a gasket to seal this passage.

The sides of plate 18 extend beyond backing structure 13 and it issecured thereto by a plurality of attachments 19 like flexible stayboltsdistributed over the area thereof. The details of the staybolts areshown in FIGURE 5. As there shown, a block 20 brazed to the outer faceof plate 18 forms a seat for the spherical head of a bolt 21 which issecured in its seat by a cap 22 screwed on the latter. Bolt 21 extendsoutwardly through a hole in plate 14 which is counterbored as at 23, toaccommodate cap 22. The counterbore has a diameter slightly greater thanthat of the cap, except in the case of the bolts along the verticalcenter line of plate 18. A compression sleeve 24 is telescoped on bolt21 and screwed into the hole. A spherical nut 25 is threaded onto bolt21 and turned tightly against the outer end of the sleeve which isshaped to fit the nut snugly. A cap 26 is screwed on the outer end ofsleeve 2- and both the cap and the inner end of sleeve 24 are providedwith sealing gaskets.

It will be evident from the foregoing that staybolts 19 securely holdthe mold side-wall plate 18 to backing structure 13 yet, by reason oftheir flexibility," permit movement of the former relative to the latteras necessitated by expansion and contraction. That is to say, plate 18may expand and contract in its own plane but is held rigidly againstmovement from or toward backing structure 13. This eliminates bowing orbuckling of plate 18.

Water boxes 27 are formed at the upper and lower corners of structure13, as viewed in FIGURE 1, for introducing cooling water into space Pand draining it there from. Thus top plates 16, which are directlyexposed to the teeming stream of molten metal and base plates 12 whichare exposed to the hot casting as it leaves the mold, are effectivelycooled.

The end walls of the mold are generally similar in construction to theside walls and are clamped between the plates 18 of the latter. Each endwall has a backing structure Z9 and a mold-wall plate 36 of channelsection sealed thereto with a cooling-water passage P therebetween.Stay-bolts l9 connect the plate to the backing structure. Cooling-waterboxes similar to those shown at 27 are provided on backing structures29.

The clamping of the side Walls to the end walls is effected by studbolts 31. These bolts extend through bushings 32 adjustably secured inhorizontal slots 33 in the side flanges 15 of backing structures 29 bybolts 34, and through horizontal slots 18a in the projecting side edgesof plates 13. Bolts 34 are inserted through horizontal slots in theflanges 15 of structures 29. This permits the mold end walls to betilted at a small angle to the vertical, to afford a slight downwardtaper to the ends of cavity C, and also allows variation in the spacingbetween opposite mold-Wall plates 30.

The bolts 31 also extend slidably through corner posts 35 ofsquare-section tube and are provided with compression springs at theirends. Posts 35 fit in the dihedral angles between plates 18 and flanges1S and are slidable on pins 36 fixed in backing structures 13 andprojecting laterally therebeyond. As shown in FIGURE 1, top and bottomhorizontal slots 13a have vertical clearance for bushings 32. Middlebushings 32 fit tightly into middle slots 18a to afford a fixed linefrom which vertical expansion occurs. Thermal-expansion stresses inplate 18 are further reduced by horizontal stress-relief slots 18b inthe portions of plates 18 extending beyond side-wall backing structures13.

The advantage of the mold of my invention is that, on expansion andcontraction of side-wall plates 18, the endwall plates move with themand no relative movement therebetween occurs. Expansion of plates 18,furthermore, reduces the stress on backing structures 13 (which do notexpand with plates 18') because staybolts 19, the only means securingthe two together (except for friction at the edges of structures 13)permit the required range of movement between their ends, i.e., theyhave a quality of flexibility.

The end walls float relative to backing structures 13 by virtue of theirslidable mounting on pins 36.

The taper of the end walls may be adjusted to the extent desired yet thejoints between side and end walls are maintained closed under heavypressure by stud bolts 31 and their springs.

Adequate provision is made for cooling plates 18 and 30 thus expeditingthe formation of a solidified skin on the exterior of the casting.

Although I have disclosed herein the preferred embodiment of myinvention, I intend to cover as well any change or modification thereinwhich may be made without departing from the spirit and scope of theinvention.

I claim:

1. A mold for continuous metal casting comprising a pair of opposedspaced side walls and a pair of opposed spaced end walls definingtherebetween a cavity for the continuous formation of a metal casting,said side walls and said end walls each comprising an inner plateadapted to contact molten metal and a backing structure for said innerplate, the inner side wall plates extending laterally beyond the edgesof the backing structures therefor, the side wall backing structuresincluding outer plates spaced from the adjacent inner side wall platesso as to define passages for cooling water between the adjacent innerand outer plates, means sealing said passages along the edges of saidouter plates, means securing said inner side Wall plates to the adjacentbacking structures so as to permit expansion of said inner plates whilepreventing movement of said plates toward and away from the adjacentbacking structures, and means for clamping the inner end wall platesbetween said inner side wall plates so that no relative movement betweensaid end Wall plates and said side wall plates occurs as said side wallplates expand and contract.

2. A mold according to claim 1 in which said means securing said innerside wall plates to the adjacent backing structures comprises aplurality of staybolts distributed over the area of said inner side wallplates.

3. A mold according to claim 1 wherein said means for clamping saidinner end wall plates includes guide pins extending from each side ofeach side wall backing structure parallel to the plane thereof, a cornerpost at each of the corners of said mold, said corner posts beingslidably mounted on said guide pins, bolts extending parallel to the endwall plates between corner posts at the same end of said mold andpermitting sliding movement of said posts With respect thereto, the endwall backing structures between said corner posts being adjustablysecured to said bolts to permit expansion and contraction,

and means at each end of the mold urging the posts at the same endtoward each other, whereby said inner end wall plates are immovablyclamped between said inner side wall plates.

4. A mold for continuous metal casting comprising a pair of opposedspaced side walls and a pair of opposed spaced end walls definingtherebetween a cavity for the continuous formation of a metal casting,said side walls and said end walls each comprising a plate adapted tocontact molten metal and a backing structure for said plate, the sidewall plates extending laterally beyond the edges of the backingstructures therefor, the side wall backing structures including outerplates spaced from the adjacent side wall plates so as to definepassages for cooling water between said outer plates and the adjacentside wall plates, means sealing said passages along the edges of saidouter plates, a plurality of staybolts distributed along the areas ofsaid side wall plates securing said plates to the adjacent backingstructures so as to permit expansion of said plates While preventingmovement of said plates toward and away from the backing structures,guide pins extending from each side of each side wall backing structureparallel to the plane thereof, a corner post at each of the corners ofsaid mold, said corner posts being slidably mounted on said guide pins,bolts extending parallel to the end wall plates between corner posts atthe same end of said mold and permitting sliding movement of said postswith respect thereto, the end wall backing structures between saidcorner posts being adjustably secured to said bolts to permit expansionand contraction, and means at each end of the mold urging the posts atthe same end toward each other, whereby said inner end wall plates areclamped between said inner side wall plates so that no relative movementoccurs therebetween as said inner side wall plates expand and contract.

5. A mold for continuous metal casting comprising a pair of opposedspaced side walls and a pair of opposed spaced end walls definingtherebetween a cavity for the continuous formation of a metal casting,said side walls and said end walls each comprisng a plate adapted tocontact molten metal and a backing structure therefor, and means forclamping said end wall plates between said side wall plates so that norelative movement occurs therehetween comprising guide pins extendingfrom each side of, each side wall backing structure parallel to theplane thereof, means slidably mounted on said pins for supporting saidend wall plates and backing structures therefor, and means for urgingsaid side wall plates together thereby clamping said end wall platesimmovably between said side Walls.

References Cited by the Examiner UNITED STATES PATENTS 2,283,450 5/1942Mitchell et al. 22l46 2,510,100 6/1950 Goss 2257.2 2,747,244 5/ 1956Goss 22-572 3,049,769 8/1962 Schultz 2257.2 XR

FOREIGN PATENTS 538,863 4/ 1957 Canada.

I. SPENCER OVERHOLSER, Primary Examiner. MARCUS U. LYONS, Examiner.

1. A MOLD FOR CONTINUOUS METAL CASTING COMPRISING A PAIR OF OPPOSEDSPACED SIDE WALLS AND A PAIR OF OPPOSED SPACED END WALLS DEFININGTHEREBETWEEN A CAVITY FOR THE CONTINUOUS FORMATION OF A METAL CASTING,SAID SIDE WALLS AND SAID END WALLS EACH COMPRISING AN INNER PLATEADAPTED TO CONTACT MOLTEN METAL AND A BACKING STRUCTURE FOR SAID INNERPLATE, THE INNER SIDE WALL PLATE EXTENDING LATERALLY BEYOND THE EDGES OFTHE BACKING STRUCTURES THEREFOR, THE SIDE WALL BACKING STRUCTURESINCLUDING OUTER PLATES SPACED FROM THE ADJACENT INNER SIDE WALL PLATESSO AS TO DEFINE PASSAGES FOR COOLING WATER BETWEEN THE ADJACENT INNERAND OUTER PLATES, MEANS SEALING SAID PASSAGES ALONG THE EDGES OF SAIDOUTER PLATES, MEANS SECURING SAID INNER SIDE WALL PLATES TO THE ADJACENTBACKING STRUCTURES SO AS TO PERMIT EXPANSION OF SAID INNER PLATES WHILEPREVENTING MOVEMENT OF SAID PLATES TOWARD AND AWAY FROM THE ADJACENTBACKING STRUCTURES, AND MEANS FOR CLAMPING THE INNER END WALL PLATESBETWEEN SAID INNER SIDE WALL PLATES SO THAT NO RELATIVE MOVEMENT BETWEENSAID END WALL PLATE AND SAID SIDE WALL PLATES OCCURS AS SAID SIDE WALLPLATES EXPAND AND CONTRACT.